text: When steel pipelines are built, they commonly consist of  10~12m long sections of steel pipe that has had a corrosion protective coating applied to it in a factory.  The factory will leave an uncoated area at each end of the pipe called a "cutback" so that when welding the pipe sections together, the coating is not damaged. Heat-shrinkable sleeves are applied onto the cutback at the field weld or "field joint" during the construction of a pipeline.
  As described above, the heat-shrinkable sleeves have an adhesive that sticks the sleeve to the cutback and the factory applied mainline coating and also acts as a corrosion protective layer.  The backing provides mechanical protection against abrasion and soil stress forces after the pipeline is buried.
  Heat wrap tape may used in addition for pipe bends, or as an alternative method for wrapping the whole pipe.